Influence of Ductile Damage Evolution on the Collapse Load of Frames

2010 ◽  
Vol 77 (3) ◽  
Author(s):  
Edwin L. Chica ◽  
Antolín L. Ibán ◽  
José M. G. Terán ◽  
Pablo M. López-Reyes
Keyword(s):  
Ductile Fracture ◽  
Damage Evolution ◽  
Damage Model ◽  
Ductile Failure ◽  
Ductile Material ◽  
Collapse Load ◽  
Local Criterion ◽  
Solid Materials ◽  
Damage Models ◽  
Isotropic Damage

In this note we analyze the influence of four damage models on the collapse load of a structure. The models considered here have been developed using the hypothesis based on the concept of effective stress and the principle of strain equivalence and they were proposed by Lemaitre and Chaboche (1990, Mechanics of Solid Materials), Wang (1992, “Unified CDM Model and Local Criterion for Ductile Fracture—I. Unified CDM Model for Ductile Fracture,” Eng. Fract. Mech., 42, pp. 177–183), Chandrakanth and Pandey (1995, “An Isotropic Damage Model for Ductile Material,” Eng. Fract. Mech., 50, pp. 457–465), and Bonora (1997, “A Nonlinear CDM Model for Ductile Failure,” Eng. Fract. Mech., 58, pp. 11–28). The differences between them consist mainly in the form of the dissipative potential from which the kinetic law of damage is derived and also in the assumptions made about some parameters of the material.

Failure Predictions for DP Steel Cross-die Test using Anisotropic Damage

2011 ◽  
Vol 21 (5) ◽  
pp. 713-754 ◽  
Author(s):  
M. S. Niazi ◽  
H. H. Wisselink ◽  
T. Meinders ◽  
J. Huétink
Keyword(s):  
Strain Rate ◽  
Damage Evolution ◽  
Damage Model ◽  
Anisotropic Damage ◽  
Continuum Damage ◽  
Anisotropic Plasticity ◽  
Continuum Damage Model ◽  
Damage Models ◽  
Isotropic Damage ◽  
Failure Predictions

The Lemaitre's continuum damage model is well known in the field of damage mechanics. The anisotropic damage model given by Lemaitre is relatively simple, applicable to nonproportional loads and uses only four damage parameters. The hypothesis of strain equivalence is used to map the effective stress to the nominal stress. Both the isotropic and anisotropic damage models from Lemaitre are implemented in an in-house implicit finite element code. The damage model is coupled with an elasto-plastic material model using anisotropic plasticity (Hill-48 yield criterion) and strain-rate dependent isotropic hardening. The Lemaitre continuum damage model is based on the small strain assumption; therefore, the model is implemented in an incremental co-rotational framework to make it applicable for large strains. The damage dissipation potential was slightly adapted to incorporate a different damage evolution behavior under compression and tension. A tensile test and a low-cycle fatigue test were used to determine the damage parameters. The damage evolution was modified to incorporate strain rate sensitivity by making two of the damage parameters a function of strain rate. The model is applied to predict failure in a cross-die deep drawing process, which is well known for having a wide variety of strains and strain path changes. The failure predictions obtained from the anisotropic damage models are in good agreement with the experimental results, whereas the predictions obtained from the isotropic damage model are slightly conservative. The anisotropic damage model predicts the crack direction more accurately compared to the predictions based on principal stress directions using the isotropic damage model. The set of damage parameters, determined in a uniaxial condition, gives a good failure prediction under other triaxiality conditions.

Characterization of Notched Ductile Failure With Continuum Damage Mechanics

1990 ◽  
Vol 112 (4) ◽  
pp. 412-421 ◽  
Author(s):  
C. L. Chow ◽  
K. Y. Sze
Keyword(s):  
Ductile Fracture ◽  
Circular Hole ◽  
Damage Mechanics ◽  
Damage Model ◽  
Ductile Failure ◽  
Continuum Damage Mechanics ◽  
Thin Plates ◽  
Continuum Damage ◽  
Anisotropic Model ◽  
Aluminum Alloy 2024

A recently developed anisotropic model of continuum damage mechanics has been applied successfully to characterize ductile fracture of cracked plates under mode I and mixed mode failures. The damage model is further extended in this investigation to examine its applicability to include notch ductile fracture of thin plates containing a circular hole. Two hole sizes of 16 mm and 24 mm diameters are chosen and the specimen material is aluminum alloy 2024-T3. Fracture loads of the plates are predicted by the damage model and compared satisfactorily with those determined experimentally. This investigation provides an important confirmation that not only the anisotropic model of continuum damage mechanics but also the same failure criterion developed can be effectively employed to characterize both ductile fracture for plates containing an isolated macro-crack or circular hole which would otherwise not be possible using the conventional theory of fracture mechanics. The successful development of the unified approach to characterize ductile failure provides a vital impetus for design engineers in the general application of the theory of continuum damage mechanics to solve practical engineering problems.

A geometrically inspired model for brittle damage in compressible elastomers

2021 ◽  
pp. 1-39
Author(s):  
Sanhita Das ◽  
Shubham Sharma ◽  
Ananth Ramaswamy ◽  
Debasish Roy ◽  
J.N. Reddy
Keyword(s):  
Phase Field ◽  
Scale Parameter ◽  
Damage Model ◽  
Continuum Damage ◽  
Surface Integral ◽  
Brittle Damage ◽  
Damage Models ◽  
Damaged Material ◽  
Isotropic Damage ◽  
Pure Compression

Abstract Regularized continuum damage models such as those based on an order parameter (phase field) have been extensively used to characterize brittle damage of compressible elastomers. However, the prescription of the surface integral and the degradation function for stiffness lacks a physical basis. In this article we propose a continuum damage model that draws upon the postulate that a damaged material could be mathematically described as a Riemannian manifold. Working within this framework with a well defined Riemannian metric designed to capture features of isotropic damage, we prescribe a scheme to prevent damage evolution under pure compression. The result is a substantively reduced stiffness degradation due to damage before the peak response and a faster convergence rate with the length scale parameter in comparison with a second order phase field formulation that involves a quadratic degradation function. We also validate this model using results of tensile experiments on double notched plates.

scholarly journals A Review of Damage, Void Evolution, and Fatigue Life Prediction Models

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 609
Author(s):  
Hsiao Wei Lee ◽  
Cemal Basaran
Keyword(s):  
Damage Evolution ◽  
Life Prediction ◽  
Prediction Models ◽  
Damage Model ◽  
Empirical Models ◽  
Type Model ◽  
Newtonian Mechanics ◽  
Damage Models ◽  
Void Evolution ◽  
Evolution Function

Degradation, damage evolution, and fatigue models in the literature for various engineering materials, mostly metals and composites, are reviewed. For empirical models established under the framework of Newtonian mechanics, Gurson–Tvergaard–Needleman (GTN) type model, Johnson-Cook (J-C) type damage model, microplasticity model, some other micro-mechanism based damage models, and models using irreversible entropy as a metric with an empirical evolution function are thoroughly discussed. For Physics-based models, the development and applications of unified mechanics theory is reviewed.

Nonlinear modeling of concentrically loaded reinforced blockwork masonry columns

2004 ◽  
Vol 31 (6) ◽  
pp. 1012-1023 ◽  
Author(s):  
Hasan Orhun Köksal ◽  
Bilge Doran ◽  
Ayse Elif Ozsoy ◽  
Sema Noyan Alacali
Keyword(s):  
Finite Element ◽  
Yield Criterion ◽  
Nonlinear Modeling ◽  
Damage Model ◽  
Three Dimensional ◽  
Mesh Size ◽  
Simple Relation ◽  
Damage Parameter ◽  
Damage Models ◽  
Isotropic Damage

Since only a limited number of experimental and analytical studies have been carried out for the purpose of developing strength design procedures for reinforced blockwork masonry columns, there is a certain need for further studies that reflect material properties and behavior of blockwork masonry more closely. This paper deals with a nonlinear finite element modeling of the concentrically loaded reinforced blockwork masonry columns making use of both elasto-plastic and isotropic damage models. If the damage model is enriched with the introduction of a simple relation for the material damage parameter that accounts for the mesh size effect, three-dimensional finite element analyses of columns for the well-known experimental works in the literature are accomplished. Finally, the predictions from both the numerical analyses and the existing expressions for the ultimate load of the masonry columns are compared with the experimental results.Key words: compressive strength, reinforced blockwork masonry column, finite element method, Drucker-Prager yield criterion, isotropic damage theory.

A Mechanical Fatigue Damage Evolution Model for PB-Free Solder Materials

2008 ◽  
Author(s):  
Leila J. Ladani ◽  
Jafar Razmi
Keyword(s):  
Damage Evolution ◽  
Pure Shear ◽  
Damage Model ◽  
Energy Partitioning ◽  
Evolution Model ◽  
Ductile Material ◽  
Anisotropic Damage ◽  
Mechanical Fatigue ◽  
The Subject ◽  
Free Solder

Evaluating state of damage in a ductile material as it experiences mechanical fatigue and cyclic loading poses much complexity and has been the subject of many researches. This study revisits the anisotropic damage model developed by Lemaitre (1992) and proposes to use his model combined with a micro-mechanics and mechanism based damage evolution model (Energy Partitioning Damage Evolution (EPDE)) and also a Unified Creep Plasticity-based model to predict the state of damage. The model is examined for pure shear and is applied to Pb-free solder materials. New anisotropic damage model exponents are generated using experimental data for Pb-free solder for both EPDE and UPC-based models and are compared with exponents generated previously under the assumption of isotropic and homogenous damage evolution.

scholarly journals An enhanced void-crack-based Rousselier damage model for ductile fracture with the XFEM

2018 ◽  
Vol 28 (6) ◽  
pp. 943-969 ◽  
Author(s):  
MIM Ahmad ◽  
JL Curiel-Sosa ◽  
S Arun ◽  
JA Rongong
Keyword(s):  
Ductile Fracture ◽  
Volume Fraction ◽  
Damage Model ◽  
Ductile Material ◽  
Integration Scheme ◽  
Extended Finite Element ◽  
Material Interfaces ◽  
Mapping Algorithm ◽  
Return Mapping ◽  
Return Mapping Algorithm

This work presents a modelling strategy for ductile fracture materials by implementing the Rousselier damage model with the extended finite element method (XFEM). The implicit integration scheme and consistent tangent modulus based on a radial return mapping algorithm for this constitutive model are developed by the user-defined material subroutine UMAT in ABAQUS/Standard. To enhance the modelling of the crack development in the materials, the XFEM is used that allows modelling of arbitrary discontinuities, where the mesh does not have to be aligned with the boundaries of material interfaces. This modelling strategy, so-called Rousselier-UMAT-XFEM (RuX) model, is proposed to connect both concepts, which gives an advantage in predicting the material behaviour of ductile material in terms of voids and crack relation. This is the first contribution where XFEM is used in ductile fracture analysis for micromechanical damage problems. The results indicate that the RuX model is a promising technique for predicting the void volume fraction damage and crack extension in ductile material, which shows a good agreement in terms of stress–strain and force–displacement relationships.

A MULTISCALE FRAMEWORK FOR CHARACTERIZATION AND MODELING DUCTILE FRACTURE IN HETEROGENEOUS ALUMINUM ALLOYS

2009 ◽  
Vol 01 (01) ◽  
pp. 21-55 ◽  
Author(s):  
SOMNATH GHOSH ◽  
D. M. VALIVETI ◽  
CHAO HU ◽  
JIE BAI
Keyword(s):  
Aluminum Alloys ◽  
Ductile Fracture ◽  
Multiscale Modeling ◽  
Damage Model ◽  
Ductile Failure ◽  
Matrix Cracking ◽  
Anisotropic Plasticity ◽  
Gtn Model ◽  
Statistical Homogeneity ◽  
Heterogeneous Microstructures

This paper develops three components contributing to the overall framework of multiscale modeling of ductile fracture in aluminum alloys. The first module is morphology-based domain partitioning (MDP) as a pre-processor to the multiscale modeling. This module delineates regions of statistical homogeneity and inhomogeneity with a systematic three-step process that is based on geometric features of morphology. The second module is detailed micromechanical analysis of particle fragmentation and matrix cracking of heterogeneous microstructures. A locally enriched VCFEM or LE-VCFEM is developed to incorporate ductile failure through matrix cracking in the form of void growth and coalescence using nonlocal Gurson–Tvergaard–Needleman (GTN) model. The third module develops a homogenized anisotropic plasticity-damage model in the form of GTN model for macroscopic analysis. Parameters in this GTN model are calibrated from results of homogenization of microstructural variables obtained from microstructural RVE. Numerical examples elucidate the strength of components of the overall framework.

An endochronic damage model for three-dimensional ductile failure analysis of double-edge notched thick-tension specimens

1998 ◽  
Vol 212 (1) ◽  
pp. 25-34
Author(s):  
C L Chow ◽  
X F Chen
Keyword(s):  
Damage Evolution ◽  
Failure Process ◽  
Damage Model ◽  
Three Dimensional ◽  
Ductile Failure ◽  
Failure Criteria ◽  
Ductile Damage ◽  
Damage Evolution Equation ◽  
Double Edge ◽  
Failure Loads

A three-dimensional ductile damage model based on the endochronic plastic theory is developed and employed to characterize the failure process of double-edge notched thick-tension specimens. A ductile damage evolution equation is derived with a new intrinsic time-scale specifically defined to characterize damage evolution. Two damage failure criteria are proposed and employed to predict the failure loads and crack initiation sites which correspond well with those measured experimentally.

An isotropic damage model for ductile material

1995 ◽  
Vol 50 (4) ◽  
pp. 457-465 ◽  
Author(s):  
S. Chandrakanth ◽  
P.C. Pandey
Keyword(s):  
Damage Model ◽  
Ductile Material ◽  
Isotropic Damage
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